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DSL at a Glance 10 Mb/S Single Twisted Pair Ethernet Study Group Nov 2016, Mario Traeber

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DSL at a Glance 10 Mb/S Single Twisted Pair Ethernet Study Group Nov 2016, Mario Traeber S(H)DSL at a Glance 10 Mb/s Single Twisted Pair Ethernet Study Group Nov 2016, Mario Traeber Connected Home Division Introduction This presentation introduces SHDSL as a technology to support the CSD for 10SPE. The focus is mostly on feasibility of a Twisted Pair PHY ranging to 1km at 10Mbps full-duplex data transmission. An introduction to the standards history, technology features and properties as well as performance characteristics will be presented. The presentation concludes with a discussion on what would need to be explored further to apply the underlying technology principles to the objectives of 10SPE. Connected Home Division Standards Overview The history of SHDSL in various standards bodies and it’s relation into IEEE SDSL and SHDSL Standardization ISDN Relationship Ÿ synchronous Ÿ 2B1Q Ÿ 144 kbit/s HDSL between ISDN, Ÿ plesiochronous Ÿ 2B1Q HDSL, HDSL2, Ÿ 2320 kbit/s (1 line) MDSL Ÿ plesiochronous MDSL, SDSL and MDSL (MuBIC) Ÿ 2B1Q Ÿ 272, 400, 528, Ÿ synchronous 784 kbit/s Ÿ TC-PAM SHDSL Ÿ Multi bitrate 160 - 1040 ANSI- kbit/s SDSL Ÿ plesiochronous HDSL2 Ÿ 2B1Q Ÿ plesiochronous ETSI- Ÿ Multi bitrate Ÿ TC-PAM Standards SDSL Ÿ 1544 kbit/s ISDN (ETSI 1988) Ÿ synchronous + plesiochronous HDSL (ETSI 1996) Ÿ TC-PAM Ÿ Multi bitrate 200 - HDSL2 (ANSI 1999) 2320 kbit/s SDSL (ETSI, 2000) SHDSL (ITU, 2000) SHDSL Ÿ synchronous + plesiochronous Ÿ TC-PAM Ÿ Multi bitrate 200 - 2320 kbit/s Connected Home Division SDSL and SHDSL Standardization (2) Major ETSI Decisions on SDSL Major ITU-T Decisions on SHDSL • Line code • Line code • PSDs • PSDs (North America) • Network synchronization • Network synchronization • Data rates • Data rates (North America) • Frame structure • Frame structure • EOC • EOC • Electrical characteristics • Electrical characteristics • Activation • Activation • Pre-activation • Pre-activation • ISDN transport • Test loops • Test loops (North America) • Noise models • Noise models (North America) • ATM annex Connected Home Division 5 SDSL and SHDSL Standardization SDSL Data Rates • Multi bit rate system • Payload bit rates 192 kbit/s - 2312 kbit/s • 8 kbit/s granularity SHDSL Data Rates • Multi bit rate system • Payload bit rates 192 kbit/s - 2304 kbit/s • North America: N• 64 kbit/s or N• 64 kbit/s + 8 kbit/s (payload) Connected Home Division SDSL and SHDSL Standardization Start Up Procedure . Activation: – Basic structure of HDSL2 activation sequence . Preactivation: – g.hs Management . Clear eoc channel . HDSL2 channel proocol Connected Home Division ITU-T G.991.2 Annex F&G (SHDSL.bis) Higher data rates TC-PAM Levels Standard Part of Data rates (Bits / Symbol: B-Channels Symbol Rates G.992.1 [kbps] Payload+OH) Z-Bits [kbaud] Annex A+B 3B + 0Z 66,7 (Standard SHDSL) 192..2312 16 (3+1) .... ... 36B + 1Z 773,3 3B + 0Z 66,7 192..3840 16 (3+1) .... ... 60B + 0Z 1282,7 Annex F+G (SHDSL.bis) 12B + 0Z 194 768...5696 32 (4+1) .... ... 89B + 0Z 1426 Connected Home Division ITU-T G.991.2 Annex F&G (SHDSL.bis) Enhanced G.994.1 (G.hs) startup G.992.1 SHDSL (old) Caplist Version 1 Standard -Bit mask for Baserates and Subrates -Enabling each single baserate and subrate -Bit mask applied to TCPAM-16 only Extension for Annex F+G Caplist Version 2: contains additionally -Ranges of Baserates per coding -3-tuple per coding TCPAM-16 and TCPAM-32 (min, max, step) Example: (40,70,10) means: 40x64kbps, 50x64kbps, 60x64kbps, 70x64kbps -Overlap of ranges is possible Connected Home Division ITU-T G.991.2 (SHDSL.bis) Multi-Channel bonding (M-Pair) Standard Part of Line Bonding Level Interleaving Interleaving G.992.1 Bonding Order of Subchannels Annex A+B Byte (Standard SHDSL) 4-wire OSI-Layer 1 Interleaving Master / Slave add-ons in Interleaving acc. Annex F+G M-Pair OSI-Layer 1 Byte to negotiatioin in (SHDSL.bis) (M=1,2..4) Interleaving Activation Frame Connected Home Division 11 xDSL rate/reach performance compared Data rate [Mbit/s] 200/100 VDSL Extended PAM levels 15 Mbps per channel 100/50 Extended reach 24/2 Standard compliant mode 5 Mbps per channel ADSL 15/15 Extended 4..128 PAM levels 5/5 G.SHDSL 16/32 PAM levels 0.1 km 1 km 3 km 5 km Reach Connected Home Division New and edited chapters ETHoverDSL @ IEEE 802.3ah (SHDSL relevant) • Clause 30 (EFM=Ethernet First Mile) • Clause 45 • Clause 57 MAC control (optional) • Clause 61 • Clause 63 MAC Standard Ethernet MII (optional) MAC PHY Rate Matching PHY PMI Aggregation Adaptation functions TPS-TC (64B/65B) PMA (PMS-TC) xDSL specific PMD Connected Home Division MAC PHY Rate matching Rate Matching Adapts the MAC/MII bit-rate (100Mbps) to the lower (aggregate) PHY bit-rate(s) MAC is operated in half-duplex mode . Note: It should still be able to transmit and receive simultaneously CRS function is used by the PHY to prevent MAC from sending another MAC frame Preamble and SFD are removed PHY needs to buffer one maximum length frame (i.e. 1522 Bytes) in both directions Connected Home Division PHY PMI Aggregation Function (PAF) PAF Connected Home Division PHY PMI Aggregation Function (PAF) PAF Provides a flexible mapping of a MAC to different PHYs Purpose is to increase the bandwidth and to provide redundancy PAF will be negotiated using g.994.1 ( 2 Phases) *) Implementation is PHY specific – Combination of 10PASS-TS and 2BASE-TL theoretically possible Restrictions – Speed ratio between fastest and slowest link must be < 4 – Differential delay <15000 bit times – Frame size between 64 and 512 Bytes with a 4 Byte granularity – Up to 32 PHYs per MAC Transmit sequence can be vendor specific *) we’ll have a dedicated session on EFM handshake and PAF Connected Home Division Encapsulation (64B/65B) TPS-TC Input is either a MAC frame or a PMI aggregation fragment A 32bit(SHDSL)/16bit (VDSL) FCS will be calculated and added at the end of each frame/fragment (“TC-frame”) This TC-frame is chopped into 64-Bytes packets One Sync-Byte is added at the beginning to indicate the content of the following 64-Bytes packet resulting in a 65-Bytes “Codeword” . Sync-Byte 0F16 indicates that all 64 following bytes are data from the very same data frame . Sync-Byte F016 requires a look at the first payload bit D1 – If Zero, wait for a frame start Byte – If not Zero it contains the position of the last Byte of the frame Connected Home Division IEEE EFM Physical layers for copper lines PMD 10PASS-TS . 10 Mbps, PASSband, Twisted Pair, Short Reach . Using VDSL2 technology . Based on ANSI T1.424/trial use standard 2BASE-TL . 2Mbps, BASE-band, Twisted Pair, Long Reach . Based on SHDSL technology . Using ITU-T G.991.2.bis standard . Allowing 32-PAM coding for higher bit-rates Connected Home Division 10PASS-TS Objectives PMD • To provide 100 Mb/s data rate at the MII. • To provide ~10Mb/s encapsulated packet data rate at the α(β) interface. • To provide full duplex operation. • To provide for operating over non-loaded voice grade twisted pair cable at distances up to 750 m (2.5 kfeet). • To provide a communication channel with a mean bit error rate, at the α(β) interface, of less than one part in 107 with 6 dB noise margin. • To provide optional support for operation on multiple pairs • All band-plans are allowed • To have only one line code Connected Home Division 2BASE-TL Objectives PMD • To provide 100 Mb/s data rate at the MII. • To provide ~2Mb/s encapsulated packet data rate at the α(β) interface. • To provide full duplex operation. • To provide for operating over non-loaded voice grade twisted pair cable at distances up to 2,700 m (9 kfeet). • To provide a communication channel with a mean bit error rate, at the α(β) interface, of less than one part in 107 with 5 dB noise margin. • To provide optional support for operation on multiple pairs • All data rates from 192 kbps up to 5696 kbps in a 64kbps granularity are supported • Focus is on 512, 704, 1024, 2048, 3072 and 5696 kbps Connected Home Division *) Bonding on OSI-Layer 1, Byte interleaving **) Bonding on OSI-Layer 2, Payload Interleaving Standards Summary Comparison of Symmetrical Data Technologies SDSL SHDSL SHDSL.bis EFM 2Base-TL 192kbps - 2.3Mbps 192..5696 kbps Data Rate 192kbps - 2.3Mbps or per pair 384kbps – 4.624Mbps Pairs 1 1 or 2 *) 1-4 *) 1..32 **) Line Code 2B1Q TC PAM 16 TC PAM 16/32 TC PAM 16 / 32 EOC Proprietary 20-bit HDLC-type Pre-activation Proprietary Standard Based G.994.1 (g.hs) Rate Adaption Yes Yes Power Back-off No Yes Repeaters No Yes Timing Synchronous Synchronous + Plesiochronous pref. Synchronous Span Power Yes Yes Connected Home Division Physical Layer How is the SHDSL PHY defined? Physical Layer Definition Trellis Encoder Spectral/ Data Tomlinson Data Scrambler Convolusional Symbol Noise In Precoder Out Encoder Mapper Shaper Echo Canceller Data Viterbi Tomlinson Linear Data Descrambler + Out Decoder Modulo Equalizer In Connected Home Division 23 Trellis Encoder – Adds redundancy PHY-TX: Trellis Encoder – Output depends on state and input (512 states) – Increases SNR – 3/4 bits in – 16/32-level PAM pulse out Y0 Input X0 Convolutional from Encoder Y1 Frame One Serial to Mapper Dimensional S Parallel . d-2 d-1 d-0 Symbol Conversion X1 Mapper Payload Data Y2 (serial stream) X2 Y3 Level S: x*1/16 Mapper: Bit-to-level mapping -15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 11 13 15 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 Y3 Trellis 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 Y2 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 Y1 Encoder 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 Y0 Output Connected Home Division PHY-TX: Convolutional Encoder Principle of a convolutional encoder Y1 X1 T0 T1 T2 Shift Register Y0 Block Diagram of a simple convolutional encoder A sequence of bits enters the encoder at the input X1.
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